'\" et
.TH termios.h "0P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\"
.SH PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
.\"
.SH NAME
termios.h
\(em define values for termios
.SH SYNOPSIS
.LP
.nf
#include <termios.h>
.fi
.SH DESCRIPTION
The
.IR <termios.h> 
header shall contain the definitions used by the terminal I/O
interfaces (see
.IR "Chapter 11" ", " "General Terminal Interface"
for the structures and names defined).
.SS "The termios Structure"
.P
The
.IR <termios.h> 
header shall define the following data types through
.BR typedef :
.IP "\fBcc_t\fP" 12
Used for terminal special characters.
.IP "\fBspeed_t\fP" 12
Used for terminal baud rates.
.IP "\fBtcflag_t\fP" 12
Used for terminal modes.
.P
The above types shall be all unsigned integer types.
.P
The implementation shall support one or more programming environments
in which the widths of
.BR cc_t ,
.BR speed_t ,
and
.BR tcflag_t
are no greater than the width of type
.BR long .
The names of these programming environments can be obtained using the
\fIconfstr\fR()
function or the
.IR getconf
utility.
.P
The
.IR <termios.h> 
header shall define the
.BR termios
structure, which shall include at least the following members:
.sp
.RS 4
.nf

tcflag_t  c_iflag     \fRInput modes.\fR
tcflag_t  c_oflag     \fROutput modes.\fR
tcflag_t  c_cflag     \fRControl modes.\fR
tcflag_t  c_lflag     \fRLocal modes.\fR
cc_t      c_cc[NCCS]  \fRControl characters.\fR
.fi
.P
.RE
.P
The
.IR <termios.h> 
header shall define the following symbolic constant:
.IP NCCS 12
Size of the array
.IR c_cc
for control characters.
.P
The
.IR <termios.h> 
header shall define the following symbolic constants for use as
subscripts for the array
.IR c_cc :
.TS
box center tab(!);
cb s | l
cb cb | cb
l | l | l.
Subscript Usage
Canonical Mode!Non-Canonical Mode!Description
_
VEOF!!EOF character.
VEOL!!EOL character.
VERASE!!ERASE character.
VINTR!VINTR!INTR character.
VKILL!!KILL character.
\&!VMIN!MIN value.
VQUIT!VQUIT!QUIT character.
VSTART!VSTART!START character.
VSTOP!VSTOP!STOP character.
VSUSP!VSUSP!SUSP character.
\&!VTIME!TIME value.
.TE
.P
The subscript values shall be suitable for use in
.BR #if
preprocessing directives and shall be distinct, except that the VMIN
and VTIME subscripts may have the same values as the VEOF and
VEOL subscripts, respectively.
.SS "Input Modes"
.P
The
.IR <termios.h> 
header shall define the following symbolic constants for use as flags
in the
.IR c_iflag
field. The
.IR c_iflag
field describes the basic terminal input control.
.IP BRKINT 12
Signal interrupt on break.
.IP ICRNL 12
Map CR to NL on input.
.IP IGNBRK 12
Ignore break condition.
.IP IGNCR 12
Ignore CR.
.IP IGNPAR 12
Ignore characters with parity errors.
.IP INLCR 12
Map NL to CR on input.
.IP INPCK 12
Enable input parity check.
.IP ISTRIP 12
Strip character.
.IP IXANY 12
Enable any character to restart output.
.IP IXOFF 12
Enable start/stop input control.
.IP IXON 12
Enable start/stop output control.
.IP PARMRK 12
Mark parity errors.
.SS "Output Modes"
.P
The
.IR <termios.h> 
header shall define the following symbolic constants for use as flags
in the
.IR c_oflag
field. The
.IR c_oflag
field specifies the system treatment of output.
.IP OPOST 12
Post-process output.
.IP ONLCR 12
Map NL to CR-NL on output.
.IP OCRNL 12
Map CR to NL on output.
.IP ONOCR 12
No CR output at column 0.
.IP ONLRET 12
NL performs CR function.
.IP OFDEL 12
Fill is DEL.
.IP OFILL 12
Use fill characters for delay.
.IP NLDLY 12
Select newline delays:
.RS 12 
.IP NL0 8
Newline type 0.
.IP NL1 8
Newline type 1.
.RE
.IP CRDLY 12
Select carriage-return delays:
.RS 12 
.IP CR0 8
Carriage-return delay type 0.
.IP CR1 8
Carriage-return delay type 1.
.IP CR2 8
Carriage-return delay type 2.
.IP CR3 8
Carriage-return delay type 3.
.RE
.IP TABDLY 12
Select horizontal-tab delays:
.RS 12 
.IP TAB0 8
Horizontal-tab delay type 0.
.IP TAB1 8
Horizontal-tab delay type 1.
.IP TAB2 8
Horizontal-tab delay type 2.
.IP TAB3 8
Expand tabs to spaces.
.RE
.IP BSDLY 12
Select backspace delays:
.RS 12 
.IP BS0 8
Backspace-delay type 0.
.IP BS1 8
Backspace-delay type 1.
.RE
.IP VTDLY 12
Select vertical-tab delays:
.RS 12 
.IP VT0 8
Vertical-tab delay type 0.
.IP VT1 8
Vertical-tab delay type 1.
.RE
.IP FFDLY 12
Select form-feed delays:
.RS 12 
.IP FF0 8
Form-feed delay type 0.
.IP FF1 8
Form-feed delay type 1.
.RE
.SS "Baud Rate Selection"
.P
The
.IR <termios.h> 
header shall define the following symbolic constants for use as values
of objects of type
.BR speed_t .
.P
The input and output baud rates are stored in the
.BR termios
structure. These are the valid values for objects of type
.BR speed_t .
Not all baud rates need be supported by the underlying hardware.
.IP B0 12
Hang up
.IP B50 12
50 baud
.IP B75 12
75 baud
.IP B110 12
110 baud
.IP B134 12
134.5 baud
.IP B150 12
150 baud
.IP B200 12
200 baud
.IP B300 12
300 baud
.IP B600 12
600 baud
.IP B1200 12
1\|200 baud
.IP B1800 12
1\|800 baud
.IP B2400 12
2\|400 baud
.IP B4800 12
4\|800 baud
.IP B9600 12
9\|600 baud
.IP B19200 12
19\|200 baud
.IP B38400 12
38\|400 baud
.SS "Control Modes"
.P
The
.IR <termios.h> 
header shall define the following symbolic constants for use as flags
in the
.IR c_cflag
field. The
.IR c_cflag
field describes the hardware control of the terminal; not all values
specified are required to be supported by the underlying hardware.
.IP CSIZE 12
Character size:
.RS 12 
.IP CS5 8
5 bits
.IP CS6 8
6 bits
.IP CS7 8
7 bits
.IP CS8 8
8 bits
.RE
.IP CSTOPB 12
Send two stop bits, else one.
.IP CREAD 12
Enable receiver.
.IP PARENB 12
Parity enable.
.IP PARODD 12
Odd parity, else even.
.IP HUPCL 12
Hang up on last close.
.IP CLOCAL 12
Ignore modem status lines.
.P
The implementation shall support the functionality associated with the
symbols CS7, CS8, CSTOPB, PARODD, and PARENB.
.SS "Local Modes"
.P
The
.IR <termios.h> 
header shall define the following symbolic constants for use as flags
in the
.IR c_lflag
field. The
.IR c_lflag
field of the argument structure is used to control various terminal
functions.
.IP ECHO 12
Enable echo.
.IP ECHOE 12
Echo erase character as error-correcting backspace.
.IP ECHOK 12
Echo KILL.
.IP ECHONL 12
Echo NL.
.IP ICANON 12
Canonical input (erase and kill processing).
.IP IEXTEN 12
Enable extended input character processing.
.IP ISIG 12
Enable signals.
.IP NOFLSH 12
Disable flush after interrupt or quit.
.IP TOSTOP 12
Send SIGTTOU for background output.
.SS "Attribute Selection"
.P
The
.IR <termios.h> 
header shall define the following symbolic constants for use with
\fItcsetattr\fR():
.IP TCSANOW 12
Change attributes immediately.
.IP TCSADRAIN 12
Change attributes when output has drained.
.IP TCSAFLUSH 12
Change attributes when output has drained; also flush pending input.
.SS "Line Control"
.P
The
.IR <termios.h> 
header shall define the following symbolic constants for use with
\fItcflush\fR():
.IP TCIFLUSH 12
Flush pending input.
.IP TCIOFLUSH 12
Flush both pending input and untransmitted output.
.IP TCOFLUSH 12
Flush untransmitted output.
.P
The
.IR <termios.h> 
header shall define the following symbolic constants for use with
\fItcflow\fR():
.IP TCIOFF 12
Transmit a STOP character, intended to suspend input data.
.IP TCION 12
Transmit a START character, intended to restart input data.
.IP TCOOFF 12
Suspend output.
.IP TCOON 12
Restart output.
.P
The
.IR <termios.h> 
header shall define the
.BR pid_t
type as described in
.IR <sys/types.h> .
.P
The following shall be declared as functions and may also be defined
as macros. Function prototypes shall be provided.
.sp
.RS 4
.nf

speed_t cfgetispeed(const struct termios *);
speed_t cfgetospeed(const struct termios *);
int     cfsetispeed(struct termios *, speed_t);
int     cfsetospeed(struct termios *, speed_t);
int     tcdrain(int);
int     tcflow(int, int);
int     tcflush(int, int);
int     tcgetattr(int, struct termios *);
pid_t   tcgetsid(int);
int     tcsendbreak(int, int);
int     tcsetattr(int, int, const struct termios *);
.fi
.P
.RE
.LP
.IR "The following sections are informative."
.SH "APPLICATION USAGE"
The following names are reserved for XSI-conformant systems to use as
an extension to the above; therefore strictly conforming applications
shall not use them:
.TS
tab(@);
le le le.
CBAUD@EXTB@VDSUSP
DEFECHO@FLUSHO@VLNEXT
ECHOCTL@LOBLK@VREPRINT
ECHOKE@PENDIN@VSTATUS
ECHOPRT@SWTCH@VWERASE
EXTA@VDISCARD
.TE
.SH RATIONALE
None.
.SH "FUTURE DIRECTIONS"
None.
.SH "SEE ALSO"
.IR "\fB<sys_types.h>\fP"
.P
The System Interfaces volume of POSIX.1\(hy2017,
.IR "\fIcfgetispeed\fR\^(\|)",
.IR "\fIcfgetospeed\fR\^(\|)",
.IR "\fIcfsetispeed\fR\^(\|)",
.IR "\fIcfsetospeed\fR\^(\|)",
.IR "\fIconfstr\fR\^(\|)",
.IR "\fItcdrain\fR\^(\|)",
.IR "\fItcflow\fR\^(\|)",
.IR "\fItcflush\fR\^(\|)",
.IR "\fItcgetattr\fR\^(\|)",
.IR "\fItcgetsid\fR\^(\|)",
.IR "\fItcsendbreak\fR\^(\|)",
.IR "\fItcsetattr\fR\^(\|)"
.P
The Shell and Utilities volume of POSIX.1\(hy2017,
.IR "Chapter 11" ", " "General Terminal Interface",
.IR "\fIgetconf\fR\^"
.\"
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
.PP
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
